This invention relates to a method for treating a varicose vein. More particularly, this invention relates to a method for eliminating a varicose vein. This invention also relates to an associated device for use in the method.
In varicose veins, the valves arc malfunctioning or destroyed so that the veins balloon at the lower ends. This condition can be particularly pronounced in certain leg veins. In a conventional surgical procedure for the treatment of varicose veins, two incisions are made in a vein, one at the ankle and one at the groin. An elongate stripper instrument is then inserted through the ankle incision and passed through the vein to the groin. At the groin, a cup is attached to the distal end of the stripper. Subsequently, the stripper is pulled down the leg so that the cup rips out the vein.
In this procedure, other veins connecting to the varicose vein are torn. The leg subsequently turns ugly shades of black and blue. Of course, the patient experiences substantial pain and suffering from the procedure.
Various means have been proposed to eliminate or close varicose veins with less surgical trauma, including damaging an inner endothelial surface of a vein with laser, electric or radio-frequency energy. Motivation for such damage is the known tendency of internally damaged circulatory vessels to collapse and remain collapsed through adhesion of damaged or mutilated surfaces; essentially a beneficial application of otherwise undesirable or post-surgical adhesion. Known means to achieve endothelial damage however generally suffer from a drawback that the intensity of energy imparted to the endothelial surface is uneven, particularly so when the vein is irregular in cross-section, and the diameter varies over a treated length.
An object of the present invention is to provide a method for treating varicose veins.
Another object of the present invention is to provide such a method which results in less pain to the patient than the conventional technique.
An additional object of the present invention is to provide such a method which generates less hematoma than the conventional technique.
A further object of the present invention is to provide such a method wherein injury to the nerves is reduced.
Yet a further object of the invention is to provide a method and device for delivering a similar treatment to arteries.
These and other objects of the present invention will be apparent from the drawings and  ed descriptions herein.
A medical method for collapsing circulatory vessels in vivo in accordance with the present invention utilizes an elongate element having an at least partially flexible appendage attached to a tip of the element. The method comprises inserting said elongate element and said appendage in a circulatory vessel of a patient and then simultaneously rotating and withdrawing the elongate element from the blood vessel, causing the appendage to describe an essentially helical contact path with an inner surface of the vessel, to thereby damage the inner surface and facilitate a permanent collapse of the vessel.
In accordance with a particular embodiment of the present invention, the appendage takes the form of a whip-like surgical steel spring or spring-tail wire component of an intravenous surgical instrument and is disposed inside the vein or other elongate circulatory vessel in a sagittal plane thereof. The wire or spring-tail is attached at a first end to a central post or shaft of an elongate tool inserted in the vein, and coils outward in the sagittal plane, substantially perpendicular to a longitudinal axis of the elongate vessel. A second end of the spring-tail is free, and tangentially and pressingly disposed along an inner surface or endothelium of the vein. During a withdrawal of the instrument the shaft is simultaneously rotated and pulled from the vessel, and the second end of the spring-tail is drawn over the endothelium in a helical or spiral pattern in which the endothelium is scored or damaged. By a proper choice of size and relaxed shape of the spring-tail, the spring-tail remains in continuous contact with the endothelium during the withdrawal with approximately constant contact area. Therefore a relatively uniform amount of damage is done to the inner vessel walls during the withdrawal operation.
In the context of this disclosure, a xe2x80x9cspring-tailxe2x80x9d may be taken explicitly to mean a short wire-element, thin enough in cross-section, and of sufficient stiffness, to withstand a significant bending strain without plastic deformation. In other words, a spring-tail is an object having the mechanical properties of a section of a coil spring having an arcuate form elastically deformable between a straight configuration on one hand and approximately a full turn of coil on the other hand.
In a second particular embodiment of the present invention, the shaft is disposed within an first insulated sheath, electrically isolating the shaft from an inner surface or wall of the vessel. The spring-tail in this embodiment serves as a first electrode, a second electrode being disposed outside of a patient, possibly in a form of a grounding strip. A current path then exists along the central post or shaft, passing through the spring-tail or first electrode, through a contact point between the first electrode and an inner wall or endothelium of the circulatory vessel, and thence diffusely to an outer surface of the patient. The contact point between the first electrode and the endothelium thereby forms a most restricted, and therefore highest resistance, portion of the current path passing through fleshy part of the patient. Consequently, a highest concentration or intensity of cellular damage attributable to current flow is realized at the contact point with the endothelium.
While a degree or concentration of damage in cells of the endothelium is enhanced by the passage of current, over purely mechanical means, a drawback of this embodiment inheres in the conductivity of human blood, which comprises a saline solution, and a resultant dilution of a contact current density by a blood borne current. This limitation is overcome or compensated in a third embodiment of the present invention. In this embodiment, a modified, composite, first electrode includes a second sheath surrounding the spring-tail. The sheath is fabricated of a high-resistance alloy, such as would be suitable for thin film heater elements, and is insulated from the tail when in a relaxed or non-deformed configuration by either an air-gap, or a filling of a non-conductive gel, such as a petroleum jelly. When pressed against an inner surface or wall of a vessel, the sheath of the composite electrode deforms by design with marginally less stiffness than the tail, and as a result the sheath and tail are brought into an internal contact in an area of contact of the second sheath with the inner wall, as more fully described hereinafter with reference to the drawings.
It will be appreciated that in a thin film of high-resistance alloy conduction is more facile across a thickness of the film than along a surface direction. Accordingly, following a deformation of the composite electrode when pressed against a vessel wall, a substantial portion of the current will pass perpendicularly across the film and into the vessel wall, and a minor portion of the current will flow along a surface direction, and leak into surrounding blood. A degree of resistive heating will also be realized in the area of contact of sheath with the inner wall, and accordingly an enhanced degree of local cellular damage.
In case it is possible to empty a blood or circulatory vessel to be collapsed, as for example in the case of veins, the second embodiment will be seen to function optimally, without the appearance of leakage currents in the blood. In case the vessel cannot be drained, as is likely in the case of arteries, it will be seen that a utilization of the more complex third embodiment is indicated.
In yet another embodiment of a vascular surgical tool in accordance with the present invention, a modified form of the second embodiment, an electrode predisposed in a hollow version of the central post or shaft is compressively coiled inside the shaft. Upon being advanced toward a distal end of the shaft, a tip of the electrode emerges therefrom and partially uncoils, forming a spring-tail configuration lying in the sagittal plane of the circulatory vessel. Following a endothelium debriding operation, the partially uncoiled electrode tip may be snipped from the tool, preparatory to exposing a fresh surface in a subsequent operation. This method of feeding a spring or wire from a central shaft has application to both a purely mechanical and an electrically facilitated abrasion of the endothelium. A different mode of deployment is contemplated in the embodiment including a conducting sheath surrounding the spring-tail, or electrode tip. In this embodiment, the electrode tip and surrounding sheath are inserted into a vein or other vessel constrained by a first sheath to lie in generally a longitudinal axis of the vessel. Prior to commencement of a abrasion operation, a relative movement of a central post or shaft and the surrounding first sheath expels the electrode tip and sheath, which components are biased towards and then assume an arcuate conformation, lying generally at right angles to the central shaft, and in the sagittal plane.